Caracterización química e isotópica de la cuenca del arroyo La Ballenera, partido General Alvarado, Provincia de Buenos Aires. Datos preliminares

CALVI, CAROLINA; DAPEÑA, CRISTINA; MARTINEZ, DANIEL E.; GUTHEIM, FLORENCIA

Santa Fe

Congreso; 2 Congreso Internacional de Hidrologia de Llanuras; 2014

UNL, FICH, CENEHA, CIM

The objective of this work is to present a preliminary hydrochemical and isotopic characterization of the waters of La Ballenera creek, located at the General Alvarado district in the Southeast of the Buenos Aires province. La Ballenera creek has 30km of length with N-S direction discharging into the Atlantic Ocean. It has sinuous habit and a narrow alluvial plain. Climate is suhhumid-humid with little or null water deficit. The chemical composition of groundwater and superficial water shows low variation and is sodium bicarbonate type. Groundwater is grouped in three isotopic systems: 1. Water more depleted in the high-middle basin (δ18O = -5.6?,δ2H= -31?), 2. water of the low basin sites at the right side of the creek (δ18O = -5.0?, δ2H= -29?); 3. Water more enriched (δ18O = -4.2?; δ2H= -23?) near the lake. Irrigation wells are more depleted all over the basin. The same behavior is observed in superficial waters, with a distinct enrichment in 18O in the lower basin, where lake waters (δ18O∼ -3,5 ?, δ2H∼-19 ?) are evaporated. Superficial waters of the high basin and the right side of the creek of the low basin are more depleted.